Why does Mn(II) show maximum paramagnetic character among the bivalent ions of the first transition series?

(a) Give reasons for the following observations: (i) Cu^(+) ion is not stable in aqueous solution. (ii) Mn (II) ion shows maximum paramagnetic character amongst the bivalent ions of first transition series. (iii) Scandium (At. no. 21) salts are white. (b) Describe the reactions involved in the preparation of K_2Cr_2O_7 from chromite ore.

The bivalent metal ion having maximum paramagnetic behavior among the first transition series element is

The bivalent metal ion having maximum paramagnetic behaviour among the first transition series elements is

Why does carbon show maximum catenation among group 14 elements ?

(i) Name the element of 3d-transition series which shows maximum number of oxidation states. Why does it show so? (ii) Which transition metal of 3d-series has positive E^0(M^(2+)//M) value and why? (iii) Out of Cr^(3+) and Mn^(3+) which is a stronger oxidizing agent and hy? (iv) Name a member of the lanthanoid series which is well known to exhibit + 2 oxidation state. (v) Complete the following equaton: MnO_(4)^(-) + 8H^(+) + 5e^(-) to

The atomic numbers of five elements A, B, C, D and E are 6, 8, 3, 7 and 9 respectively. (i) Which is the element having the highest electropositivity among these elements ? Why? (ii) Which is the element having the least metallic character among these elements ? Why? (iii) What is your conclusion about the relationship between metallic character and electropositivity of an element ?

How would you account for the following: (i) The atomic radii of the metals of the third (5d) series of transition elements are virtually the same as those of the corresponding members of the second (4d) series. (ii) The E^0 value for the Mn^(3+)//Mn^(2+) couple is much more positive than that for Cr^(3+)//Cr^(2+) couple or Fe^(3+)//Fe^(2+) couple.